Jacques Simard’s international research contributed to the discovery of breast, ovarian and prostate cancer susceptibility genes BRCA1 and BRCA2, resulting in a genetic predisposition test used worldwide. His international studies on deciphering the genetic architecture of breast cancer, provided the long-awaited knowledge to develop personalized risk assessment tools to improve prevention and early detection of the disease, targeting women most likely to benefit, especially through a populational risk stratified screening approach.